I agree with SS, the Dead were never overtly political like the Airplane, CSN, Bruce Springsteen, Don Henley, Dixie Chicks, etc. They played a few benefits, but they never seemed to take a certain side. I have listened to/watched thousands of hours of Dead audio and video and they never said Nixon sucked or Reagan sucked or whatever.
"Don't ask me what I think of you, I might not give the answer that you want me to."
- Pete Green